Multilayer capacitors, which are often referred to as “chips,” are commonly used for bypass, coupling, or energy storage applications in electronic circuits. The capacitor includes internal parallel plates and a dielectric body, which may be made of a ceramic. Alternating parallel plates are connected by respective terminations. Each of the end terminations may then be electrically coupled to corresponding plates and provide an external electrical connection to the multilayer capacitor.
Ceramic capacitors may be electrical power sources for many applications. The most common applications are in consumer electronics. While being generally reliable for these applications, ceramic capacitors tend to suffer catastrophic failure when utilized in high power, rapid discharge applications. At catastrophic failure, the capacitor ceases to function. For ceramics, this is typically the result of dielectric breakdown that creates a short circuit between any two of the opposing internal plates. When a capacitor short circuits, uncontrolled electrical flow through the capacitor may damage other electrical components in the circuit. The capacitor at that point is useless and may also render the attached electrical circuit inoperative. Because ceramic capacitors may be generally unreliable in high power, rapid discharge, they are not often used in those applications. In applications where high power, rapid discharge, and high reliability are required, polymer capacitors are favored.
In a polymer capacitor, the polymer is the dielectric. Polymer capacitors are advantageous in a number of respects. They may be made with very large areas from large films or sheets of the polymer. For example, polymer capacitors may have hundreds of square feet of polymer in one capacitor. In addition, the polymer dielectric has a high voltage capability and generally does not fail catastrophically. These characteristics enable polymer capacitors having both high-energy density and high reliability to be economically made.
Due to the demanding nature of the high-energy storage applications, and to be a commercially viable alternative, ceramic capacitors are needed that are capable of storing large amounts of energy and that have large energy density. Because energy stored is a function of the charged voltage squared of the capacitor, high voltage capability, for example, up to or in excess of 10 kV, is needed. In addition, capacitor assemblies are needed which are reliable under rapid charging and discharging of large amounts of stored energy. There is a desire to be able to choose a ceramic capacitor for high energy storage because ceramic capacitors can discharge more quickly than other types of capacitors, such as, polymer capacitors.